E-Coli Tools/Materials needed: Red Tool Box containing forceps, petri dish with nutrient agar, millipore filter, syringe, incubator, graduated 10 ml cylinder, lighter. How to conduct the test: At the site: Clean the end of the forceps with the lighter to clean off any possible bacteria that might be on them. Unscrew the Millipore Filter, and using the cleaned forceps, place the grid paper on the filter part gride side up. Then Screw the "cup" section back on. Attach the syringe to the rubber tube, and the tube to the bottom part of the Millipore Filter. Collect 10 ml of water from the source being tested, and pour it into the "cup" part of the MIllipore Filter over the grid paper. Then attach the top to the cup part. Put your finger over the remaining hole of the base of the MIllipore Filter, and pull on the syringe. This will cause the water to be suctioned through the grid paper and the filter. Then, take your finger off the hole, and push the syringe back in. Then put your finger back, and pull again on the syringe. Repeat this process until all the water has been sucked through the filter. When all the water has been sucked through, unscrew the top. Use the forceps to put the grip paper onto the agar in the Petri dish, grid side up. Put the top of the Petri dish back on. In the classroom: PUt the Petri dish in the incubator upside down for 24 hours. After 24 hours, count how many colonies of Ecoli you can see on the grid paper and report the results. Significance of the test/ typical results: By testing for E Coli you can determine how safe the water is to drink and swim in. The general rule of thumb is water with E Coli 100 colonies/ 10 ml of water or larger is not safe to swim in, and water with 10 colonies/10 ml or smaller is safe to drink.
Tools/Materials needed: Red Tool Box containing forceps, petri dish with nutrient agar, millipore filter, syringe, incubator, graduated 10 ml cylinder, lighter.
How to conduct the test:
At the site: Clean the end of the forceps with the lighter to clean off any possible bacteria that might be on them. Unscrew the Millipore Filter, and using the cleaned forceps, place the grid paper on the filter part gride side up. Then Screw the "cup" section back on. Attach the syringe to the rubber tube, and the tube to the bottom part of the Millipore Filter. Collect 10 ml of water from the source being tested, and pour it into the "cup" part of the MIllipore Filter over the grid paper. Then attach the top to the cup part. Put your finger over the remaining hole of the base of the MIllipore Filter, and pull on the syringe. This will cause the water to be suctioned through the grid paper and the filter. Then, take your finger off the hole, and push the syringe back in. Then put your finger back, and pull again on the syringe. Repeat this process until all the water has been sucked through the filter. When all the water has been sucked through, unscrew the top. Use the forceps to put the grip paper onto the agar in the Petri dish, grid side up. Put the top of the Petri dish back on.
In the classroom: PUt the Petri dish in the incubator upside down for 24 hours. After 24 hours, count how many colonies of Ecoli you can see on the grid paper and report the results.
Significance of the test/ typical results: By testing for E Coli you can determine how safe the water is to drink and swim in. The general rule of thumb is water with E Coli 100 colonies/ 10 ml of water or larger is not safe to swim in, and water with 10 colonies/10 ml or smaller is safe to drink.